Ac2-26 activated the AKT1/GSK3ß pathway to reduce cerebral neurons pyroptosis and improve cerebral function in rats after cardiopulmonary bypass.

BACKGROUND: Cardiopulmonary bypass (CPB) results in brain injury, which is primarily caused by inflammation. Ac2-26 protects against ischemic or hemorrhage brain injury. The present study was to explore the effect and mechanism of Ac2-26 on brain injury in CPB rats. METHODS: Forty-eight rats were randomized into sham, CPB, Ac, Ac/AKT1, Ac/GSK3ßi and Ac/AKT1/GSK3ßa groups. Rats in sham group only received anesthesia and in the other groups received standard CPB surgery. Rats in the sham and CPB groups received saline, and rats in the Ac, Ac/AKT1, Ac/GSK3ßi and Ac/AKT1/GSK3ßa groups received Ac2-26 immediately after CPB. Rats in the Ac/AKT1, Ac/GSK3ßi and Ac/AKT1/GSK3ßa groups were injected with shRNA, inhibitor and agonist of GSK3ß respectively. The neurological function score, brain edema and histological score were evaluated. The neuronal survival and hippocampal pyroptosis were assessed. The cytokines, activity of NF-κB, S100 calcium-binding protein ß(S100ß) and neuron-specific enolase (NSE), and oxidative were tested. The NLRP3, cleaved-caspase-1 and cleaved-gadermin D (GSDMD) in the brain were also detected. RESULTS: Compared to the sham group, all indicators were aggravated in rats that underwent CPB. Compared to the CPB group, Ac2-26 significantly improved neurological scores and brain edema and ameliorated pathological injury. Ac2-26 reduced the local and systemic inflammation, oxidative stress response and promoted neuronal survival. Ac2-26 reduced hippocampal pyroptosis and decreased pyroptotic proteins in brain tissue. The protection of Ac2-26 was notably lessened by shRNA and inhibitor of GSK3ß. The agonist of GSK3ß recovered the protection of Ac2-26 in presence of shRNA. CONCLUSIONS: Ac2-26 significantly improved neurological function, reduced brain injury via regulating inflammation, oxidative stress response and pyroptosis after CPB. The protective effect of Ac2-26 primarily depended on AKT1/ GSK3ß pathway.

Protein phosphatase 2A activators reverse age-related behavioral changes by targeting neural cell senescence.

The contribution of cellular senescence to the behavioral changes observed in the elderly remains elusive. Here, we observed that aging is associated with a decline in protein phosphatase 2A (PP2A) activity in the brains of zebrafish and mice. Moreover, drugs activating PP2A reversed age-related behavioral changes. We developed a transgenic zebrafish model to decrease PP2A activity in the brain through knockout of the ppp2r2c gene encoding a regulatory subunit of PP2A. Mutant fish exhibited the behavioral phenotype observed in old animals and premature accumulation of neural cells positive for markers of cellular senescence, including senescence-associated ß-galactosidase, elevated levels cdkn2a/b, cdkn1a, senescence-associated secretory phenotype gene expression, and an increased level of DNA damage signaling. The behavioral and cell senescence phenotypes were reversed in mutant fish through treatment with the senolytic ABT263 or diverse PP2A activators as well as through cdkn1a or tp53 gene ablation. Senomorphic function of PP2A activators was demonstrated in mouse primary neural cells with downregulated Ppp2r2c. We conclude that PP2A reduction leads to neural cell senescence thereby contributing to age-related behavioral changes and that PP2A activators have senotherapeutic properties against deleterious behavioral effects of brain aging.

Active DNA demethylation promotes cell fate specification and the DNA damage response.

Neurons harbor high levels of single-strand DNA breaks (SSBs) that are targeted to neuronal enhancers, but the source of this endogenous damage remains unclear. Using two systems of postmitotic lineage specification-induced pluripotent stem cell-derived neurons and transdifferentiated macrophages-we show that thymidine DNA glycosylase (TDG)-driven excision of methylcytosines oxidized with ten-eleven translocation enzymes (TET) is a source of SSBs. Although macrophage differentiation favors short-patch base excision repair to fill in single-nucleotide gaps, neurons also frequently use the long-patch subpathway. Disrupting this gap-filling process using anti-neoplastic cytosine analogs triggers a DNA damage response and neuronal cell death, which is dependent on TDG. Thus, TET-mediated active DNA demethylation promotes endogenous DNA damage, a process that normally safeguards cell identity but can also provoke neurotoxicity after anticancer treatments.

Locomotion activates PKA through dopamine and adenosine in striatal neurons.

The canonical model of striatal function predicts that animal locomotion is associated with the opposing regulation of protein kinase A (PKA) in direct and indirect pathway striatal spiny projection neurons (SPNs) by dopamine1-7. However, the precise dynamics of PKA in dorsolateral SPNs during locomotion remain to be determined. It is also unclear whether other neuromodulators are involved. Here we show that PKA activity in both types of SPNs is essential for normal locomotion. Using two-photon fluorescence lifetime imaging8-10 of a PKA sensor10 through gradient index lenses, we measured PKA activity within individual SPNs of the mouse dorsolateral striatum during locomotion. Consistent with the canonical view, dopamine activated PKA activity in direct pathway SPNs during locomotion through the dopamine D1 receptor. However, indirect pathway SPNs exhibited a greater increase in PKA activity, which was largely abolished through the blockade of adenosine A2A receptors. In agreement with these results, fibre photometry measurements of an adenosine sensor11 revealed an acute increase in extracellular adenosine during locomotion. Functionally, antagonism of dopamine or adenosine receptors resulted in distinct changes in SPN PKA activity, neuronal activity and locomotion. Together, our results suggest that acute adenosine accumulation interplays with dopamine release to orchestrate PKA activity in SPNs and proper striatal function during animal locomotion.

Neuronal subset-specific phosphatase and tensin homolog knockout mice exhibit age and brain region-associated alterations in microglia/macrophage activation.

Seizures induce brain region-dependent enhancements in microglia/macrophage activation. Neuronal subset-specific phosphatase and tensin homolog (PTEN) knockout (KO) mice display hyperactive mammalian target of rapamycin (mTOR) signaling in the hippocampus, cerebellum, and cortex followed by seizures that increase in severity with age. To determine if KO mice also exhibit alterations in the spatiotemporal activation pattern of microglia, we used flow cytometry to compare the percentage of major histocompatibility complex-II activated microglia/macrophages between KO and wildtype (WT) mice at 5, 10, and 15 weeks of age. At 5 weeks, microglia/macrophage activation was greater in the cortex, P < 0.001, cerebellum, P < 0.001, and hippocampus, P < 0.001, of KO compared to WT mice. At 10 weeks, activation was greatest in the cortex of KO mice, P < 0.001, in the cerebellum of WT mice, P < 0.001, but similar in the hippocampus, P > 0.05. By 15 weeks, activation in the hippocampus was more than 25 times greater in KO mice compared to WT mice, P < 0.001. We show that hyperactive mTOR signaling is associated with an altered spatiotemporal pattern of microglia/macrophage activation in the brain and induces an enhanced neuroimmune response in the hippocampus.

Female sexual behavior is disrupted in a preclinical mouse model of PCOS via an attenuated hypothalamic nitric oxide pathway.

Women with polycystic ovary syndrome (PCOS) frequently experience decreased sexual arousal, desire, and sexual satisfaction. While the hypothalamus is known to regulate sexual behavior, the specific neuronal pathways affected in patients with PCOS are not known. To dissect the underlying neural circuitry, we capitalized on a robust preclinical animal model that reliably recapitulates all cardinal PCOS features. We discovered that female mice prenatally treated with anti-Müllerian hormone (PAMH) display impaired sexual behavior and sexual partner preference over the reproductive age. Blunted female sexual behavior was associated with increased sexual rejection and independent of sex steroid hormone status. Structurally, sexual dysfunction was associated with a substantial loss of neuronal nitric oxide synthase (nNOS)-expressing neurons in the ventromedial nucleus of the hypothalamus (VMH) and other areas of hypothalamic nuclei involved in social behaviors. Using in vivo chemogenetic manipulation, we show that nNOSVMH neurons are required for the display of normal sexual behavior in female mice and that pharmacological replenishment of nitric oxide restores normal sexual performance in PAMH mice. Our data provide a framework to investigate facets of hypothalamic nNOS neuron biology with implications for sexual disturbances in PCOS.

Dipeptidylamino-tripeptidylcarboxypeptidase NEMP3 and DPP3 (DPP III) are the same protein.

Earlier it was shown that a group of extracellular low-specific metallopeptidases is present in the mammalian brain Kropotova and Mosevitsky (2016) [1]. These enzymes are weakly connected to the axonal ends of neurons. They were named Neuron bound Extracellular MetalloPeptidases (NEMP). The enzyme named NEMP3 turned out to be a unique exopeptidase that exhibits two activities: it removes the dipeptide from the N-end of the peptide, and it can also remove the tripeptide from the C-end of the peptide. Therefore, NEMP3 possesses the activities of dipeptidylaminopeptidase and of tripeptidylcarboxypeptidase. Mass spectrometry has revealed a homology of NEMP3 with DPP3 (DPP III, EC3.4.14.4), known as cytosolic dipeptidylaminopeptidase. We isolated DPP3 from rat and bovine liver and brain by the procedures used for this purpose by other authors. The effect of DPP3 on test peptides is the same as that of NEMP3. In particular, all DPP3 samples delete the tripeptide (AKF) from the C-end of the test peptide blocked at the N-end. The data obtained show that NEMP3 and DPP3 are the same protein (enzyme). Thus, DPP3 has two exopeptidase activities: the previously known activity of dipeptidylaminopeptidase and the activity of tripeptidylcarboxypeptidase discovered in this study. Another discovery is the extracellular activity of DPP 3 in the mammalian brain near synapses, which controls neuropeptides. DPP3 is involved in various processes, but in many cases its role remains to be clarified. The results obtained in this study will be useful for solving these questions.

The p21-activated kinases in neural cytoskeletal remodeling and related neurological disorders.

The serine/threonine p21-activated kinases (PAKs), as main effectors of the Rho GTPases Cdc42 and Rac, represent a group of important molecular switches linking the complex cytoskeletal networks to broad neural activity. PAKs show wide expression in the brain, but they differ in specific cell types, brain regions, and developmental stages. PAKs play an essential and differential role in controlling neural cytoskeletal remodeling and are related to the development and fate of neurons as well as the structural and functional plasticity of dendritic spines. PAK-mediated actin signaling and interacting functional networks represent a common pathway frequently affected in multiple neurodevelopmental and neurodegenerative disorders. Considering specific small-molecule agonists and inhibitors for PAKs have been developed in cancer treatment, comprehensive knowledge about the role of PAKs in neural cytoskeletal remodeling will promote our understanding of the complex mechanisms underlying neurological diseases, which may also represent potential therapeutic targets of these diseases.

Structure-Activity Relationship in the Leucettine Family of Kinase Inhibitors.

The protein kinase DYRK1A is involved in Alzheimer's disease, Down syndrome, diabetes, viral infections, and leukemia. Leucettines, a family of 2-aminoimidazolin-4-ones derived from the marine sponge alkaloid Leucettamine B, have been developed as pharmacological inhibitors of DYRKs (dual specificity, tyrosine phosphorylation regulated kinases) and CLKs (cdc2-like kinases). We report here on the synthesis and structure-activity relationship (SAR) of 68 Leucettines. Leucettines were tested on 11 purified kinases and in 5 cellular assays: (1) CLK1 pre-mRNA splicing, (2) Threonine-212-Tau phosphorylation, (3) glutamate-induced cell death, (4) autophagy and (5) antagonism of ligand-activated cannabinoid receptor CB1. The Leucettine SAR observed for DYRK1A is essentially identical for CLK1, CLK4, DYRK1B, and DYRK2. DYRK3 and CLK3 are less sensitive to Leucettines. In contrast, the cellular SAR highlights correlations between inhibition of specific kinase targets and some but not all cellular effects. Leucettines deserve further development as potential therapeutics against various diseases on the basis of their molecular targets and cellular effects.

The Potential Role of Human NME1 in Neuronal Differentiation of Porcine Mesenchymal Stem Cells: Application of NB-hNME1 as a Human NME1 Suppressor.

This study aimed to investigate the effects of the human macrophage (MP) secretome in cellular xenograft rejection. The role of human nucleoside diphosphate kinase A (hNME1), from the secretome of MPs involved in the neuronal differentiation of miniature pig adipose tissue-derived mesenchymal stem cells (mp AD-MSCs), was evaluated by proteomic analysis. Herein, we first demonstrate that hNME1 strongly binds to porcine ST8 alpha-N-acetyl-neuraminide alpha-2,8-sialyltransferase 1 (pST8SIA1), which is a ganglioside GD3 synthase. When hNME1 binds with pST8SIA1, it induces degradation of pST8SIA1 in mp AD-MSCs, thereby inhibiting the expression of ganglioside GD3 followed by decreased neuronal differentiation of mp AD-MSCs. Therefore, we produced nanobodies (NBs) named NB-hNME1 that bind to hNME1 specifically, and the inhibitory effect of NB-hNME1 was evaluated for blocking the binding between hNME1 and pST8SIA1. Consequently, NB-hNME1 effectively blocked the binding of hNME1 to pST8SIA1, thereby recovering the expression of ganglioside GD3 and neuronal differentiation of mp AD-MSCs. Our findings suggest that mp AD-MSCs could be a potential candidate for use as an additive, such as an immunosuppressant, in stem cell transplantation.

P5A ATPase controls ER translocation of Wnt in neuronal migration.

The Wnt family contains conserved secretory proteins required for developmental patterning and tissue homeostasis. However, how Wnt is targeted to the endoplasmic reticulum (ER) for processing and secretion remains poorly understood. Here, we report that CATP-8/P5A ATPase directs neuronal migration non-cell autonomously in Caenorhabditis elegans by regulating EGL-20/Wnt biogenesis. CATP-8 likely functions as a translocase to translocate nascent EGL-20/Wnt polypeptide into the ER by interacting with the highly hydrophobic core region of EGL-20 signal sequence. Such regulation of Wnt biogenesis by P5A ATPase is common in C. elegans and conserved in human cells. These findings describe the physiological roles of P5A ATPase in neural development and identify Wnt proteins as direct substrates of P5A ATPase for ER translocation.

Protective effect of sargahydroquinoic acid against Aß25-35-evoked damage via PI3K/Akt mediated Nrf2 antioxidant defense system.

Alzheimer's disease (AD) is a progressive neurodegenerative disease characterized by memory loss and cognitive impairment. ß-Amyloid (Aß) is widely accepted as the main neurotoxin that triggers mitochondrial-associated oxidative stress, leading to neuronal death in AD. Following our preliminary research on the neuroprotective effects of the brown alga Sargassum serratifolium, its major compounds, including sargaquinoic acid, sargahydroquinoic acid (SHQA), and sargachromenol, were investigated to elucidate the antioxidant and anti-apoptotic properties of Aß25-35-stimulated PC12 cells. SHQA exhibited the most potent effect on Aß-induced mitochondrial-associated oxidative stress and apoptosis. In addition, the compound enhanced the expression and translocation of nuclear factor-E2-related factor 2 (Nrf2), while reducing the expression of cytoplasmic Kelch-like ECH-associated protein 1 (Keap1). Furthermore, the compound upregulated the expression of Nrf2-regulated antioxidant enzymes, including HO-1, NQO1, GCLc, GCLm, and TrxR1. Co-treatment with SHQA and LY294002, a specific PI3K inhibitor, inhibited nuclear Nrf2 expression and Akt phosphorylation, demonstrating that SHQA-mediated Nrf2 activation was directly associated with the PI3K/Akt signaling pathway. Mechanistic studies indicate that activation of the PI3K/Akt/Nrf2 pathway is the molecular basis for the neuroprotective effects of SHQA. In silico docking simulation revealed that SHQA established specific interactions with the key amino acid residues of PI3K, Akt, and Nrf2-Keap1 via hydrogen bonding and van der Waals interactions, which may affect the biological capacities of target markers. Overall, this is the first report of this novel mechanism of SHQA as a Nrf2 activator against Aß-mediated oxidative damage, suggesting that the compound might be a potential agent for the prevention of AD.

The mechanism of sevoflurane post-treatment alleviating hypoxic-ischemic encephalopathy by affecting histone methyltransferase G9a in rats.

Hypoxic-ischemic encephalopathy (HIE) is recognized as the main cause of neonatal death, and efficient treatment strategies remain limited. This study aims to investigate the mechanism of sevoflurane (SF) post-treatment in alleviating HIE in rats. The HIE rat model and oxygen-glucose deprivation (OGD) cell model were established, and adeno-associated virus (AAV)-histone-lysine N-methyltransferase EHMT2 (G9a) was transfected after SF treatment. The learning and memory ability and the levels of nerve growth factor (NGF)/brain-derived neurotrophic factor (BDNF) were evaluated and determined. The levels of G9a/histone H3 lysine 9 dimethylation (H3K9me2) and the enrichment level of H3K9me2 in the promoter region of BDNF gene were analyzed. After SF post-treatment, the neurons in cerebral cortex, the learning and memory skills and the contents of NGF/BDNF were increased, while the apoptosis and G9a/H3K9me2 levels were reduced. After overexpression of G9a in vitro/vivo, the enrichment levels of H3K9me2 in the promoter region of BDNF were increased, the levels of BDNF were decreased, the neurons were damaged and the learning and memory abilities of HIE rats were impaired. The conclusion is that SF post-treatment can promote the expression of BDNF by inhibiting H3K9me2 on the BDNF gene promoter and inhibiting G9a, thus alleviating HIE in rats.

Botanical Drug Puerarin Ameliorates Liposaccharide-Induced Depressive Behaviors in Mice via Inhibiting RagA/mTOR/p70S6K Pathways.

BACKGROUND: The depressive symptom hallmarks the progression of the neurodegenerative diseases, especially Alzheimer's disease. Bacterial infection is related to inflammation and depression. The present project thereby examined whether botanical drug puerarin could attenuate liposaccharide- (LPS-) induced depressive behaviors in mice. METHODS: Adult male C57BL/6N mice were sequentially treated with LPS and puerarin and evaluated for the depressive behaviors by tail suspension test and forced swim test. The brain tissues were profiled for the molecular targets of puerarin by next-generation RNA sequencing technique. Candidate targets were further verified in LPS-treated mice, neural stem cells, and highly differentiated PC12 cell line. RESULTS: Puerarin ameliorated LPS-induced depression in the mice. RNA sequencing profiles revealed that puerarin altered the expression of 16 genes while markedly downregulated Ras-related GTP-binding protein A (RagA) in LPS-treated mice. The effect of puerarin on RagA expression was confirmed by immunostaining, Western blot, and quantitative real-time PCR (qRT-PCR). Biochemical studies showed that puerarin inhibited RagA/mTOR/p70S6K pathway, attenuated the accumulation of mTORC1 in close proximity to lysosome, and reduced the production of proinflammatory cytokines. CONCLUSIONS: Botanical drug puerarin attenuated inflammation and depressive behaviors in LPS-challenged mice by inhibiting RagA/mTOR/p70S6K pathways. Puerarin may be a lead compound for the new antidepressant drugs.

Temporal proteomics during neurogenesis reveals large-scale proteome and organelle remodeling via selective autophagy.

Cell state changes are associated with proteome remodeling to serve newly emergent cell functions. Here, we show that NGN2-driven conversion of human embryonic stem cells to induced neurons (iNeurons) is associated with increased PINK1-independent mitophagic flux that is temporally correlated with metabolic reprogramming to support oxidative phosphorylation. Global multiplex proteomics during neurogenesis revealed large-scale remodeling of functional modules linked with pluripotency, mitochondrial metabolism, and proteostasis. Differentiation-dependent mitophagic flux required BNIP3L and its LC3-interacting region (LIR) motif, and BNIP3L also promoted mitophagy in dopaminergic neurons. Proteomic analysis of ATG12-/- iNeurons revealed accumulation of endoplasmic reticulum, Golgi, and mitochondria during differentiation, indicative of widespread organelle remodeling during neurogenesis. This work reveals broad organelle remodeling of membrane-bound organelles during NGN2-driven neurogenesis via autophagy, identifies BNIP3L's central role in programmed mitophagic flux, and provides a proteomic resource for elucidating how organelle remodeling and autophagy alter the proteome during changes in cell state.

Tacrine Induces Endoplasmic Reticulum-Stressed Apoptosis via Disrupting the Proper Assembly of Oligomeric Acetylcholinesterase in Cultured Neuronal Cells.

Acetylcholinesterase inhibitors (AChEIs), the most developed treatment strategies for Alzheimer's disease (AD), will be used in clinic for, at least, the next decades. Their side effects are in highly variable from drug to drug with mechanisms remaining to be fully established. The withdrawal of tacrine (Cognex) in the market makes it as an interesting case study. Here, we found tacrine could disrupt the proper trafficking of proline-rich membrane anchor-linked tetrameric acetylcholinesterase (AChE) in the endoplasmic reticulum (ER). The exposure of tacrine in cells expressing AChE, e.g., neurons, caused an accumulation of the misfolded AChE in the ER. This misfolded enzyme was not able to transport to the Golgi/plasma membrane, which subsequently induced ER stress and its downstream signaling cascade of unfolded protein response. Once the stress was overwhelming, the cooperation of ER with mitochondria increased the loss of mitochondrial membrane potential. Eventually, the tacrine-exposed cells lost homeostasis and underwent apoptosis. The ER stress and apoptosis, induced by tacrine, were proportional to the amount of AChE. Other AChEIs (rivastigmine, bis(3)-cognitin, daurisoline, and dauricine) could cause the same problem as tacrine by inducing ER stress in neuronal cells. The results provide guidance for the drug design and discovery of AChEIs for AD treatment. SIGNIFICANCE STATEMENT: Acetylcholinesterase inhibitors (AChEIs) are the most developed treatment strategies for Alzheimer's disease (AD) and will be used in clinic for at least the next decades. This study reports that tacrine and other AChEIs disrupt the proper trafficking of acetylcholinesterase in the endoplasmic reticulum. Eventually, the apoptosis of neurons and other cells are induced. The results provide guidance for drug design and discovery of AChEIs for AD treatment.

Neurotoxicity of a pyrethroid pesticide deltamethrin is associated with the imbalance in proteolytic systems caused by mitophagy activation and proteasome inhibition.

Pyrethroids are one of the most commonly used classes of synthetic pesticides in the world. Recent laboratory and epidemiological evidence suggested that pyrethroids have potential adverse effects in the mammalian brain; however, the underlying mechanisms of the neurotoxic effects of pyrethroids have not been fully elucidated. In the present study, we investigated the mechanisms of effects of a type II pyrethroid deltamethrin (DM) in a neuronal cell model focusing on the proteolytic function, including autophagy and the ubiquitin-proteasome system. We confirmed that a micromolar concentration of DM dose-dependently decreased the cell viability and induced apoptotic cell death. Our results showed that DM enhanced autophagy in association with an accumulation of autophagosomes and increase in the levels of autophagy markers LC3-II/LC3-I ratio and p62 which were much elevated in the presence of lysosomal inhibitors bafilomycin A1 and chloroquine. We also found that DM caused a dysfunction of mitochondria with a decrease of mitochondrial membrane potential and mitochondrial DNA copy number as well as colocalization with autophagosomes. Moreover, a decrease in the activities of three major proteasomal enzymes and an accumulation of ubiquitinated proteins were observed by the exposure to DM. Transcriptome analysis revealed that up-regulated genes supported the activation of autophagy with induction of cellular stress responses including oxidative stress and endoplasmic reticulum stress, while down-regulated genes related to the cell cycle and DNA replication. These findings provide novel insights into the neurotoxicity of DM which underlie the imbalance in proteolytic function caused by mitophagy activation and proteasome inhibition.

Curcumin Alleviates Oxygen-Glucose-Deprivation/Reperfusion-Induced Oxidative Damage by Regulating miR-1287-5p/LONP2 Axis in SH-SY5Y Cells.

Oxidative stress-induced neuronal damage is a main cause of ischemia/reperfusion injury. Curcumin (Cur), the principal constituent extracted from dried rhizomes of Curcuma longa L. (turmeric), exhibits excellent antioxidant effects. Previous studies have indicated that miR-1287-5p was downregulated in patients with ischemic stroke. Additionally, we predicted that Lon Peptidase 2, Peroxisomal (LONP2), which is involved in oxidative stress regulation, is targeted by miR-1287-5p. The aim of the current study is to investigate the effect of Cur on ischemia/reperfusion damage and its underlying mechanism. To mimic ischemia/reperfusion damage environment, SH-SY5Y cells were subjected to oxygen-glucose-deprivation/reperfusion (OGD/R). OGD/R treatment downregulated miR-1287-5p and upregulated LONP2 in SH-SY5Y cells, but Cur alleviated OGD/R-induced oxidative damage and reversed the effect of OGD/R on the expression of miR-1287-5p and LONP2. Furthermore, we confirmed the interactive relationship between miR-1287-5p and LONP2 (negative regulation). We revealed that miR-1287-5p overexpression alleviated OGD/R-induced oxidative damage alleviation, similar to the effect of Cur. MiR-1287-5p inhibition accentuated OGD/R-induced oxidative damage in SH-SY5Y cells, which was reversed by Cur. The expression of LONP2 in OGD/R-treated SH-SY5Y cells was decreased by miR-1287-5p overexpression and increased by miR-1287-5p inhibition, and Cur counteracted the increase in LONP2 expression induced by miR-1287-5p inhibition. In conclusion, we suggest that Cur alleviates OGD/R-induced oxidative damage in SH-SY5Y cells by regulating the miR-1287-5p/LONP2 axis. The findings provide a theoretical basis for the clinical application of curcumin.

Curcumin-Coumarin Hybrid Analogues as Multitarget Agents in Neurodegenerative Disorders.

Neurodegenerative diseases have a complex nature which highlights the need for multitarget ligands to address the complementary pathways involved in these diseases. Over the last decade, many innovative curcumin-based compounds have been designed and synthesized, searching for new derivatives having anti-amyloidogenic, inhibitory of tau formation, as well as anti-neuroinflammation, antioxidative, and AChE inhibitory activities. Regarding our experience studying 3-substituted coumarins with interesting properties for neurodegenerative diseases, our aim was to synthesize a new series of curcumin-coumarin hybrid analogues and evaluate their activity. Most of the 3-(7-phenyl-3,5-dioxohepta-1,6-dien-1-yl)coumarin derivatives 11-18 resulted in moderated inhibitors of hMAO isoforms and AChE and BuChE activity. Some of them are also capable of scavenger the free radical DPPH. Furthermore, compounds 14 and 16 showed neuroprotective activity against H2O2 in SH-SY5Y cell line. Nanoparticles formulation of these derivatives improved this property increasing the neuroprotective activity to the nanomolar range. Results suggest that by modulating the substitution pattern on both coumarin moiety and phenyl ring, ChE and MAO-targeted derivatives or derivatives with activity in cell-based phenotypic assays can be obtained.

In-silico screening and microsecond molecular dynamics simulations to identify single point mutations that destabilize ß-hexosaminidase A causing Tay-Sachs disease.

ß-hexosaminidase A (HexA) protein is responsible for the degradation of GM2 gangliosides in the central and peripheral nervous systems. Tay-Sachs disease occurs when HexA within Hexosaminidase does not properly function and harmful GM2 gangliosides begin to build up within the neurons. In this study, in silico methods such as SIFT, PolyPhen-2, PhD-SNP, and MutPred were utilized to analyze the effects of nonsynonymous single nucleotide polymorphisms (nsSNPs) on HexA in order to identify possible pathogenetic and deleterious variants. Molecular dynamics (MD) simulations showed that two mutants, P25S and W485R, experienced an increase in structural flexibility compared to the native protein. Particularly, there was a decrease in the overall number and frequencies of hydrogen bonds for the mutants compared to the wildtype. MM/GBSA calculations were performed to help assess the change in binding affinity between the wildtype and mutant structures and a mechanism-based inhibitor, NGT, which is known to help increase the residual activity of HexA. Both of the mutants experienced a decrease in the binding affinity from -23.8 kcal/mol in wildtype to -20.9 and -18.7 kcal/mol for the P25S and W485R variants of HexA, respectively.